Electron-capture-delayed fission properties of sup 234 Am

Journal Article · Thu Feb 01 00:00:00 EST 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.41.618· OSTI ID:7165387

Hall, H L; Gregorich, K E; Henderson, R A; Gannett, C M; Chadwick, R B; Leyba, J D; Czerwinski, K R; Kadkhodayan, B; Kreek, S A; Lee, D M; Nurmia, M J; Hoffman, D C ^[1]; Palmer, C E.A.; Baisden, P A ^[2]

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1. Nuclear Science Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (USA)
2. Nuclear Chemistry Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (USA)

Delayed fission following the electron-capture decay of {sup 234}Am was studied. The {sup 237}Np({alpha},7{ital n}){sup 234}Am reaction with multiple {sup 237}Np targets was used to produce {sup 234}Am. The fission properties and half-life of {sup 234}Am were measured using a rotating-wheel system. The half-life of {sup 234}Am was determined to be 2.32{plus minus}0.08 min from measurements of the fission activity. A highly asymmetric mass-yield distribution was observed for the fission activity, and the average total kinetic energy of the fission fragments was found to be 173{plus minus}5 MeV. Radiochemical separations confirmed the elemental assignment of the fissioning species to americium or fission from short-lived excited states in its EC daughter, plutonium. The cross section for {sup 234}Am produced by this reaction and decaying by electron capture was determined to be 5.4{plus minus}1.3 {mu}b by measuring the intensities of the daughter plutonium {ital K} x rays in radiochemically separated americium samples. The branching ratio of the 6.46-MeV {alpha} peak of {sup 234}Am was found to be (3.9{plus minus}1.2){times}10{sup {minus}4} in on-line measurements. The delayed-fission probability was determined to be (6.6{plus minus}1.8){times}10{sup {minus}5} from the measured ratio of fissions to plutonium {ital K} x rays. The observed fissions were unambiguously assigned to an EC-delayed fission process by measuring fissions coincident with the {ital K}-capture x rays.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7165387
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 41:2; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

652020* -- Nuclear Properties & Reactions
A=220 & above
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA REACTIONS
AMERICIUM 234
AMERICIUM ISOTOPES
BETA DECAY
BRANCHING RATIO
CHARGED-PARTICLE REACTIONS
CHEMICAL ANALYSIS
CROSS SECTIONS
DATA
DAUGHTER PRODUCTS
DECAY
ELECTRON CAPTURE DECAY
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
FISSION
FISSION YIELD
HALF-LIFE
HEAVY NUCLEI
INFORMATION
ISOTOPES
LEPTONS
MASSLESS PARTICLES
NEPTUNIUM 237 TARGET
NEUTRINOS
NUCLEAR DECAY
NUCLEAR REACTION YIELD
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
QUANTITATIVE CHEMICAL ANALYSIS
RADIOCHEMICAL ANALYSIS
TARGETS
YIELDS